Monday, 8 February 2016

Olympus Focus Stacking - OM-D EM-1 Firmware 4.x

I love creating macro images. In the past I have used various means to achieve this even building my own lens and bellows to get a 5x magnification so I guess you could call me an enthusiast of all things small. I've used focus stacking techniques in photoshop to improve the otherwise minuscule depth of field that plagues macro shots. A short time ago I changed down from full frame Canon to the Olympus OM-D EM-1 and what can I say, I've just played with another feature that has made my day. In body camera stacking. Wow. Just Wow.

Before we get going and I show you why my toungue is hanging out of my head like a happy dog, lets first see what a couple of vanilla images look like at f/2.8 and f/8. All of the images I've included here are SOOC JPEG at Fine Resolution / Maximum size.
f2.8 focussed on the washer

f/8 focussed on the washer
Out of these two shots, the f/8 yields the kind of result I'm used to. Reasonable depth of field given its a close focussed macro. You can go up more f/16 or f/22 but for my money the image starts to degrade after f/8 so I tend to hover here. To get better depth of field I would in the past have been manually focussing in steps and then stacking them all later on.

First up, lets turn the feature on. It's buried quite deep in menus and since I'll probably use this a lot I'll try and figure out how to put this on one of the plethora of function buttons.

Open Shooting Menu using the Menu button then scrolling, turn on Bracketting

Select focus bracketting

and turn it on

Turn on focus stacking from within Focus bracketting

set the depth you want to have - i.e. the depth of field you want

Differential of 1

The camera exposed two shots at slightly different focus steps and produced this final stacked shot. It has more depth of field than the f/8 shot but not much.
Focus differential of 1

Differential of 5

The camera exposed six frames and produced this final stacked shot. This is quite a bit better than the f/8 result.

Differential of 10

This time the camera exposed fifteen shots and what an amazing outcome. This is about 1.5cm of depth from a macro where you normally get about half of one mm.

It goes backward!

One thing I note is that the focus seems to assume you want to go backwards and steps away from the camera, this might be because I focussed as near as I could to the lens and it had no choice. I'll have to experiment more. When I read "bracketting" I assume it will by default go equally forwards and backwards by default. This is certainly workable and needs some more play.

When you're using 10 you might notice some focus banding with softer areas. I do see one softer area on top of the washer.

Bugbear

I really wish that the camera would use a different name for the final stacked image or have something in the metadata. If you're listing Olympus this would be an great improvement on this otherwise awesome feature. This will help you find them without having to review them all.

Caveats

The Focus Stacking feature is only available on the OM-D EM-1 although the focus bracketing is available on its little brother the OM-D EM-5. You then need to manually stack in your tool of choice afterwards if you're shooting with the EM-5.

The feature only works (currently) with three lenses:
  • Olympus 60mm Macro f/2.8
  • Olympus 12-40 f/2.8
  • Olympus 40-150 f/2.8 (also works with the teleconverter on)
While the images used to make the stack are all recorded as per your current settings, the final stacked image is only available as a JPEG regardless of other settings.

Conclusion

This is an awesome feature and is just the next step in enjoying this camera. This few second task in camera from a touch of setup and one finger button press replaces literally hours of work in photoshop. The focus banding is slightly annoying because when doing it manually this wouldn't happen but I reckon I prefer this being essentially lazy I find that this feature is going to go the distance with me.